The State Department said on Saturday that reports of multiple casualties in Syria's Duma following an alleged chemical attack were "frightening" and, if confirmed, would require an immediate response from the international community.
"These reports, if confirmed, are frightening and require an immediate response from the international community," said State Department spokeswoman Heather Nowert.
Referring to the history of the use of chemical weapons by the government of Syrian President Bashar al-Assad, Nauert stressed that Damascus and Russia, which supports it, should be held responsible for this alleged attack and added that "any new attacks should be prevented immediately. ».
"Russia, with its firm support for the regime, bears the ultimate responsibility for these violent attacks," Nauert said.
A Syrian rebel group on Saturday accused government forces of carrying out a deadly chemical attack on Duma, the last rebel-held area of eastern Guta, with an aid group saying 35 people had been killed.
Syrian state media have denied that the government army launched a chemical attack, adding that rebels in Duma are on the verge of collapse and are spreading false news.
The Syrian government has recaptured almost all of eastern Guta from the rebels in the operation that began in February and now only the Duma is under the control of the Islamist group Jais al-Islam.
Government forces, backed by Russia, bombed the area heavily on Friday afternoon, after several days of calm.
The Syrian Observatory for Human Rights said Saturday that 11 people had died in the Duma as a result of suffocation caused by a bomb dropped by government forces. According to the same NGO, a total of 70 people experienced respiratory problems after dropping this bomb.
Rami Abdel Rahman, director of the Syrian Observatory for Human Rights, said he could not confirm whether chemical weapons had been used.